NEMA 23 is a term used to describe a size of a stepper motor with a 2.3-inch square faceplate. It is a standard size used in many applications and is commonly used in CNC machines, 3D printers, and other types of automation equipment. The term “NEMA” stands for National Electrical Manufacturers Association, which sets standards for electrical equipment in the United States. The size of a NEMA 23 motor is typically measured in millimeters or inches and is specified by the width and height of the faceplate.